Table 2.

Crude and age-adjusted prevalence of different refractive errors.

Items	N	Crude prevalence (95%CI)	Age, gender-adjusted prevalence (95%CI)	P
Myopia				<0.001
Urban	1,840	75.75% (74.01%, 77.42%)	82.71% (80.89%, 84.38%)
Rural	1,297	61.97% (59.78%, 63.95%)	71.76% (69.24%, 74.15%)
Over all	3,137	69.37% (68.01%, 70.70%)	–
Low myopia				<0.001
Urban	930	61.22% (58.78%, 63.68%)	70.52% (67.76%, 73.13%)
Rural	801	50.16% (47.61%, 52.52%)	58.54% (55.34%, 61.67%)
Over all	1,731	55.55% (53.80%, 57.29%)	–
Moderate myopia				<0.001
Urban	494	45.61% (42.68%, 48.62%)	50.88% (46.65%, 55.09%)
Rural	296	27.11% (24.51%, 29.78%)	32.16% (28.25%, 36.34%)
Over all	790	36.32% (34.33%, 38.37%)
High myopia				<0.001
Urban	416	41.39% (38.31%, 44.41%)	38.68% (33.73%, 43.87%)
Rural	200	20.08% (17.65%, 22.62%)	21.55% (17.78%, 25.87%)
Over all	616	30.78% (28.80%, 32.84%)	–
Hyperopia				<0.001
Urban	178	7.33% (6.40%, 8.50%)	5.63% (4.78%, 6.63%)
Rural	286	13.66% (12.26%, 15.20%)	10.21% (8.85, 11.75%)
Over all	464	10.26% (9.41%, 11.18%)	–
Astigmatism				0.379
Urban	1,107	45.57% (43.53%, 47.50%)	46.07% (44.00%, 48.15%)
Rural	847	40.47% (38.37%, 42.58%)	44.69% (42.37%, 47.02%)
Over all	1,954	43.21% (41.77%, 44.66%)	–
Anisometropia				0.013
Urban	196	8.07% (7.02%, 9.19%)	7.27% (6.27%, 8.42%)
Rural	111	5.30% (4.44%, 6.37%)	5.41% (4.47%, 6.54%)
Over all	307	6.79% (6.09%, 7.56%)	–

CI, Confidence Interval.